Hi all, I've never used a mailing list before, so I hope this message will reach PETSc users and experts and someone might be willing to help me. I am also novice in PETSc. I have developed an unstructured finite volume solver on top of PETSc libraries. In sequential, it works like a charm. For the parallel version, I do domain decomposition externally with Metis, and work out local and global numberings, as well as communication patterns between processor. (The latter don't seem to be needed for PETSc, though.) When I run my program in parallel, it also works, but I miss values in vectors' ghost points. I create vectors with command: VecCreate(PETSC_COMM_WORLD, &x); Is it possible to get the ghost values if a vector is created like this? I have tried to use VecCreateGhost, but for some reason which is beyond my comprehension, PETSc goes berserk when it reaches the command: VecCreateGhost(PETSC_COMM_WORLD, n, PETSC_DECIDE, nghost, ifrom, &x) Can anyone help me? Either how to reach ghost values for vector created by VecCreate, or how to use VecCreateGhost properly? Kind regards, Bojan